Lathe-tool.



' FgH. HALSIEAD. I'

, LATHE TOOL.

APPLICATION FILED 001.3, I9Ie.

Patented Apr. 8, 1919.

Inventor. Fredercelaiead @JM Y narran erratas rarnnr onirica.

FREDERICK HENRY HALSTEAD, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TORIVETT LATI-IE AND GRINDER COMPANY, CF FANEUIL, MASSACHUSETTS, A.

CORPORATION OF MASSACHUSETTS.

LATHn-'roon Specification of Letters Patent.

Patented Apr. s, 1919.

To all whom t may concern:

Be it known that I, FREDERICK HENRY HALs'rnAD, a citizen of the UnitedStates, and a resident of Worcester, county of Worcester, and State ofMassachusetts, have .invented an Improvement in Lathe-Tools, of whichthe following description, in connection with the accompanying drawings,is a specification, like characters on the drawings representing likeparts.

This invention pertains to improvements in metal working apparatus andmore particularly, though not exclusively to thread cutting toolsandapparatus for presenting such tools to the work. The type of tool towhich my invention is particularly applicable is that disclosed in thepatent to Herman Dock, numbered 632,678, and in thepatent to EdwardRivett, No. 652,643, wherein a cutter disk is used which has a pluralityof cutting points which increase progressively in length and which areadapted to be progressively presented to the work to cut screw threadsand the like. Among the objects of my invention are to provide a moresimple tool holder which is more certain in its operation than thoseheretofore used, and in which the change of cutting edge is more easilyand quickly effected to provide greater rigidity of the parts, increaseddurability, and improved means for taking up any wear which may occur,while keeping the tool free from lost motion or chatter, and to providean improved close adjustment for determining the depth of the cut.

The drawings show a preferred construction of one illustrativeembodiment of my invention.

Figure 1'is a side elevation showing the cutter and its improved holder;

Fig. 2 is a vertical transverse section partly in elevation, on the line2 2 of Fig. 1;

Fig. 3 is a vertical, longitudinal Section partly in elevation on theline 3-3 of Fig. 2; and

Fig. 4 is a vertical, longitudinal section partially broken away andpartly in elevation on the line 4-4 of Fig. 2.

In the illustrative embodiment of my invention shown in the drawings, Iprovide a cutter disk 11 having a plurality of cutter points, hereinshown as ten, which cutting points are of progressively increasinglength tion of the tool holder. .preferably provided for oscillating theele- .ment 13. Coperating with the above to progage the cutter disk andbegin to fore the cutter tooth previously engaging the and of thegeneral type shown in the patent to Dock k632,67 8. These cutting pointsare adapted to he progressively presented to the work by the followingmechanism:

I prefer that the cutter 11 be bored with a taper and mounted forrotative'movement on the tapered arbor 12 which is mounted on buteccentric to an oscillatory element 13 mounted in a bearing ,14 in thestock or body por- A hand lever 15 is duce the desired step by steprotation of the cutter 13 I preferably provide a pawl 16 adapted toengage the surfaces 17 of the cutter 11 as the axis of the latter ismoved through an arc about the axis of the oscillatory element 13 bymanual movement of the lever 15.vv To properly position each cuttingpoint I providea support18, herein shown as a set screw adapted tosuccessively engage the heels of the cutting points. f Stops 19 and 2()are provided to limit the stroke of the lever 15.

In tools of this class it has heretofore been necessary to rectilinearlyretract the cutter suliciently to clear the support 18 prior toinitiating the rotary movement of the cutter I ldisk about its axis. Bymy invention I am enabledtoimpart a combined upward and backwardmovement to the cutter disk, the axis of the latter moving in anupwardly inclined arc at the beginning of its movement. I accomplishthis by locating the axis of the cutter wheel 11 at a higher point thanthe axis of the oscillatory element 13. Thus the heel of the cutterresting on the support 18 is moved upwardly at the beginning of thecutter tooth changing stroke, and consequently I am enabled to have thepawl 16 enturn it besupport 18 is sufficiently retracted to clear suchsupport without such upward movement. This greatly reduces the distancethrough which it is necessary to move the manually operable lever toeffect the change of cutting teeth. Also on the return stroke of theactuating lever the arcuate path of the axis of the cutter disk isadvantageous for the pawl 16 may rotate the cutter disk a little fartherthan is absolutely necessary without interference of the cutter diskwiththe support 18 on its return stroke. In fat it is an advantage to movethe disk such farther distance for it insures the proper positioningofthe heel 0f the cutter tooth on the support 18, the excess movementbeing compensated for by a slight reverse rotation of the cutter diskabout its axis when the heel of the cutter tooth touches the support 18prior to the completion of the return stroke of the manually operablelever 15.

To hold the lever in itsforward position during each cutting operation,I preferably provide locking means typified by the pawl 21 pivoted at 22to fthe lever 15 and radapted to be engaged with the notch 23 bypressure kof the spring 24 acting on fthe rod 26 pivoted at 27 to alever 28 which with the `pawl 21 forms a bell crank on the axis`22. lTheoperator may disengage the paw-l 21 from the notch 2,3 by pressure ofvhis thumb on the top of the rod 24, while grasping the lever 15 to pullit back into the position shown in dotted lines in Fig. 1. Dur-ing thismovement the eccentric position :of the axis of the cutter llcauses thelatter to be lifted ,away from the support 18 and retracted through anare toward the pawl 16 which engages vthe front of the adjacent cutterand imparts a partial rotation lto the cutter :wheel 11. The returnmovement of the lever 15 moves the cutter wheel forward and positionsthe next cutter on the support 18.

To provide for a change of .cutter wheels for cutting threads ofdi'erent kinds, the cutter wheel 11 is removable.. To prevent the cutterwheel from being incorrectly alined and to prevent `it from being undulytightened, I preferably provide, as shown, expansion means for securingthe tapered arbor 12 in place. In the illustrative embodiment shown inthe drawings I have effected this result by providing the tapered arbor12 with an axial aperture 29, preferably of uniform cross section andadapted to t over a boss 80 which is preferably threaded and countersunkas shown and` fitted with a screw 31 adapted lto expand the `boss 30, aportion of which is preferably slotted as shown in Fig. 1. By this meansthe arbor 12 is firmly vheld without being so firmly pressed againstvthe cutter wheel 11 as unduly yto resist rotation of the latter. Alsothe use of such expansive or internal gripping mea-ns for the arbor 24perm-its the latter to fbe spaced away from Vthe surface 32 oftheyoscillatory element 18 so that wear between the tapered surfaces lofthe arbor 12 and cutter wheel 11 may be taken up without machining. Theboss 3Q and the described `mechanism for holding the arbor 12 i-n placevinsure correct positioning and alinement of the latter.

To provide for taking up wear of the Voscillatory element 13, WthQutlateral .diS-

termine the depth of the thread, I have made the bearing 14 rotatable,its exterior surface being eccentric toits inner surface. As a means forturning the bearing 14, I preferably provide gear teeth 34 on itsexterior surface adapted to mesh with a worm 3'5 on a shaft 36 providedwith a knurled thumb nut 37 and with calibrations 38. The

gear teeth need only extend around a por-y tion of the periphery of thebearing, such teeth being preferably disposed on opposite sides of vitscenter of eccentricity. The teeth may be somewhat elongated tocompensate for variation in the position of the bearing 14 as it isadjusted longitudinally of the screws The operation of the device may bebriefly described as follows: The ltool having been set up on thecarriage of the lathe, the inclination determining screw 89 is adjustedso that the cutters have the desired pitch, the nut 40 is then tightenedfirmly to position kthe-tool on the lathe carriage. After the yproperfeed gears for the .screw cutting feed of the lathe have 'been providedand the cutter wheel is positioned, as shown in Fig 1, with the vfirstor shortest cutter resting on the support 18., the initial cut is made.The operator then presses on the top `off the rod 24, therebywithdrawing the locking pawl 21 from the .notch 23, and draws back thellever l5 until it strikes the stop 19. This moves the cutter disk 11through an are, the center of which is the axis of the oscillatoryelement 13, while the pawl 16 moves ythe cutter wheel approximately onetenth of a revolution about the arbor l2. The tool is thus withdrawnfrom the cut andthe carriage is returned to its initial position. Themovement of the disk about its center is preferably a little more thanone tenth of a revolution so that on the return stroke of the lever 13when the carriage is in position to begin the next cut, the wheel of thecutter point next in order of operation will .abut against the support18 before the lever has entirely returned to its initial posi-tion, `thecutter Iturning back a little on the arbor 12 before the lever abllts onthe stop 20. This insures contact between the heel 0f the cutter and theSupport 18. The 4foregoing operation is repeated until all ten cutterpoints have operated,maki1g the thread complete- By means of the closeadjustment providedby varying the position of the axis of theoscillatory element, .very erect work .can be performed,

while the limited length of stroke of the lever rendered possible by thearcuate path of the axis of the cutter wheel 1l, greatly increases thespeed of the change of cutter points, while rendering less likely theimproper functioning of the device becausey y of short stroking by anunskilled or careless operator, or because of uneven grinding of thecutter teeth. y

It will be understood that I have show and described one embodiment ofmy invention but that changes involving alteration,

combination of a main oscillatory shaft; a

cutter disk having a plurality of cutting points and rotatably mountedon an axis eccentric to and above the axis of said oscillatory shaft; asupport for a cutting point of said disk disposed below the axis of saidcutter disk; and means coperating with said cutter disk and saidoscillatory shaft for imparting step by step partial rotation to saidcutter disk when the axis of said cutter disk is moved to and frothrough an arc by oscillation of said oscillating shaft.

2. In a tool of the class described, the combination of a mainoscillatory shaft; a cutter' disk having a plurality of cutting pointsand rotatably mounted on an axis eccentric to and above the axis of saidoscillatory shaft; means for limiting rotation of the cutter diskagainst the cutting strain; and means coperating with said cutter diskand'said oscillatory shaft for imparting step by step partial rotationto said cutter disk when the axis of said cutter disk ismoved to and frothrough an arc by oscillation of said oscillating shaft.

3. In a tool of the class described, the

combination of a main oscillatory shaft; a

cutter disk having a plurality of cutting points and rotatably mountedon an axis eccentric to and above the axis of said oscillatory shaft; asupport for a cutting point of said disk below the axis of said disk; apawl for imparting partial rotation to said cutter disk when said cutterydisk is moved through an arc upwardly and rearwardly relative to saidsupport, said pawl initiating rotative movement of said cutter diskprior to the movement of said cutting point to a position rearward ofsaid support.

4. In a tool of the class described, the combination of a mainoscillatory shaft; a cutter disk rotatably mounted on an axis eccentricto and above the axis of said oscilmeans for imparting a greaterrotative movement to said cutter disk than the space between theadjacent cutters thereof, said support imparting reverse rotation tosaid disk as said disk is returned to operating position.

5. In a tool of the class described, a cutter disk having a centerbearing surface, an arbor therefor, a moving element for imparting a toand fro movement to said arbor to actuate partial rotation of said diskabout said arbor, a boss projecting from said moving element into saidarbor, and expansion means yfor causing said boss interiorly to engagesaid arbor.

6. In a tool of the class described, a main oscillatory shaft having atapered bearing surface, a tapered bearing therefor, a cutter wheelrotatably mounted on a bearing eccentric to said main oscillatory shaft,and means for relatively moving together into close-fitting relationsaid tapered bearing surface and said tapered bearing while maintainingunchanged laterally the position of said cutter wheel.

7. In a tool of the class described, the combination of a mainoscillatory shaft., a cutter disk rotatably mounted in a bearingeccentric to said shaft, a main bearing for said main shaft, aneccentric bearing for said main bearing, and means for imparting rotarymovement to said eccentric bearing, whereby the axis of said shaft maybe adjusted to or from the work.

8. In a tool of the class described, the

points and rotatably mounted on said shaft and having an axis eccentricto said shaft;

a support for a cutting point of said disk; and means coperating withsaid cutter disk and said oscillatory shaft imparting stepby-steppartial rotation to said cutter disk when the axis of said cutter diskis moved to and fro through an arc by oscillation of said oscillatingshaft; the initiation of movement of said oscillatory shaft to move saidcutter out of cutting position moving said cutting point away from saidsupport.

9. In a tool of the class described, the combination of a mainoscillatory shaft; a cutter disk having a plurality of cutting pointsand rotatably mounted on an am's eccentric to and carried by saidoscillatory shaft; a support for a cutting point of said disk; and meansfor imparting a greater rotating movement to said cutter disk than thespace between the adjacent cutters thereof; said support impartingreverse rotation to said disk as said disk is returned to operatingposition.

10. In a tool of the class described, a cutter disk having a centerbearing surface, an arbor therefor, a moving element for 1mparting ato-and-fro movement to said arbor to actuate partial rotation of saidcutter disk about said arbor, a boss projecting from said moving elementinto said arbor, and expansion means for locking lsaid arbor againstrotation relative to said boss.

11. In a tool of the class described, the combination of a mainoscillatory shaft, a cutter disk rotatably mounted on a bearingeccentric to said shaft, a body portion having a bearing for said shaft,a` lever for oscillating said shaft, a locking pavvl pivoted to saidlever, a notch lin said body portion for engagement With said pavvl forholding said lever, said shaft and said cutter in operating position,and a paWl controlling device movable Withsaid lever for disengagingsaid paWl from said notch during the cutter disk rotating stroke of saidlever,

12. In a toOloOf the class described, the combination of a mainoscillatory shaft; a cutter disk having a plurality of cutting pointsand rotatably mounted on an aXis eccentric to and carried 'by saidoscillatory shaft; a support for a cutting point of said disk; meanscoperating With said cutter disk and saidoscillatory shaft for impartingstep-by-step partial rotation to said cutter disk when the aXis `of saidcutter disk is moved through an arc by oscillation of said oscillatingshaft; and means for locking said `oscillatory shaft against oscillationWhen each partial rotation ofl said cutter disk is complete.

13. In a tool of the class described, a cutter disk 11 having aplurality of cutting points; an oscillatory element 13 rotatably andeccentrically carrying said cutter disk; a pavvl 16 coperating with saidoscillatory element 13 to produce step-by-step rotation of said cutter;a support 18 to prevent rotation of the cutter disk during the cuttingoperation; and locking means preventing oscillation of said oscillatoryelement during the `cutting operation.

141. In a tool of the class described, the combination of a mainoscillatory shaft 13, a cutter disk 11 rotatably mounted on an axis.eccentric to and carried by said shaft; means coperating With saidcutter disk and said shaft for imparting .SQP-by-Step rotation to saidcutter disk when the axis of said cutter disk is moved to and frothrough an arc by ocsillation of ysaid shaft; a support opposingrotation of said disk during the cutting operation; a handle lever 15for oscillating said shaft, the axis of said shaft and the axis of saidcutter disk being relatively positioned to move said cutter disk awayfrom said support on the initiation of oscillation of said shaft by saidlever.

15. In a tool of the class described, the combination of an oscillatorylever; a cutter disk having a plurality of cutting points rotatablymounted on an axis eccentric to the axis of oscillation of said lever,the axis of said cutter disk being positioned relative to the axis ofoscillation of said lever to provide for movement of said cutter disk inthe arc of a circle above the axis of oscillation of said lever; andmeans coperating With said cutter disk and said lever for impartingstep-by-step partial rotation to said cutter disk when the aXis of saidcutter disk is moved to and fro through an arc by oscillation of saidlever.

In testimony whereof I have signed my name to this specification,

FREDERICK HENRY HALSTEAD.

Copies of -this patent may be obtained for five cents each, byaddressing the Commissioner of Patents, Washington, D. G.

